I don't know. I feel that the changes are having the opposite effect of the stated intent
Make no mistake, this achievement will still be a challenge for most: the main plot requires overcoming each of the “HARD” rated dungeons, and content in most of these areas has become somewhat more randomised to avoid boring, scum-X-factor-to-win gameplay approaches. We’re pretty excited to see how these changes are received, particularly since we want to encourage more adaptive gameplay over locked dungeon tactics.
Adding an extra boss ends up increasing
the amount of scumming. Too many bosses are an auto-lose for most classes (Bleaty) or can make it impossible for certain classes to win without really specific circumstances (Tower of Goo and berserker). So now, in addition to everything else, you have to keep re-rolling until you get a beatable boss, or the player has to restrict themselves to only using the most powerful classes to avoid frustrating upsets.
Moreover, adding an extra boss hedges out marginal strategies. Dungeons that were already hard to beat without ideal combinations are now even harder. The result is that the randomization makes those perfect spawns more important, not less.
To keep the game fresh, I don't think we need more randomness. I think we need better fleshing out of marginal options and more player control over the RNG.